Why does my closure property on a SKLabelNode subclass become nil?

Question

I have the following SKLabelNode subclass:

class ButtonNode: SKLabelNode {
    // The only reason this is optional is because of the required init() method.
    private var buttonAction: (() -> Void)?

    init(_ text: String, action: @escaping () -> Void) {
        self.buttonAction = action

        // Initialise the button label node.
        super.init(fontNamed: "Futura")
        self.isUserInteractionEnabled = true
        self.text = text
        self.fontColor = SKColor.white
    }

    override init() {
        super.init()
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        if touches.first?.location(in: self) != nil {
            self.buttonAction?()
        }
    }
}

I then instantiate the ButtonNode using:

let button = ButtonNode("Label", action: { print("Action called") })

This doesn't work as I expect it to (the action is never called). Upon investigating I discovered that:

In my intialiser the buttonAction property is not nil
In the touchesBegan method, the buttonAction property is nil

Why does the buttonAction property get set to nil?

Why does my closure property on a SKLabelNode subclass become nil?

0 Answers0